6 min read Low-Level Design: Bank Account Transaction System The bank account transaction system LLD models accounts, transactions, and balance management with strong […] Read article
6 min read System Design: Distributed Tracing System (Jaeger/Zipkin-style) Distributed tracing tracks a single request as it propagates through microservices, allowing engineers to Read article
6 min read Low-Level Design: Online Code Judge (LeetCode-style) The online code judge LLD involves designing a system that accepts code submissions, compiles Read article
5 min read Prefix Sum Interview Patterns Prefix sums transform range sum queries from O(n) to O(1) after O(n) preprocessing. They also underlie Read article
7 min read Low-Level Design: Splitwise (Expense Sharing App) The Splitwise LLD asks you to model a shared expense tracker where users add Read article
6 min read Low-Level Design: Pub/Sub Message Broker A Pub/Sub (Publish-Subscribe) message broker decouples producers from consumers through named topics. Producers publish events; Read article
7 min read Low-Level Design: Food Delivery App (DoorDash / Uber Eats) The food delivery app LLD question asks you to model the Read article
7 min read Consistent Hashing: System Design Deep Dive Consistent hashing is a distributed hashing scheme that minimises key remapping when nodes are Read article
6 min read Low-Level Design: Task Scheduler The Task Scheduler is a recurring LLD interview question at companies like Google, Meta, Airbnb, and Read article
5 min read Interval Problem Fundamentals Interval problems involve ranges [start, end] and ask about overlaps, merges, insertions, or optimal scheduling. The key Read article
9 min read Problem Statement Design a social network graph system like LinkedIn’s connection model or Facebook’s friends graph. Users can send friend Read article
8 min read Problem Statement Design a stock trading order book system. Traders submit buy and sell orders at specific prices and quantities. Read article
7 min read The 0/1 Knapsack Pattern The 0/1 Knapsack problem is one of the most important DP patterns — its structure appears Read article
9 min read Problem Statement Design an online auction system like eBay. Sellers list items with a starting price, auction duration, and reserve Read article
8 min read Problem Statement Design a search autocomplete (typeahead) system like Google Search suggestions or Amazon product search. As a user types, Read article
